In ring laser gyros it is important for obvious reasons to have a gyro with a long lifetime. In the past, the goal was to create an ultra pure helium and neon gas environment inside the laser cavity of a ring laser gyro. However, it has been discovered that a slight oxygen background extends the life of the ring laser gyro by reducing degradation caused by the plasma. In present ring laser gyros 1 shown in FIG. 1, helium neon plasma 12 is introduced into a ring laser gyro block 2 to create lasing in the ring laser gyro 1 which in turn creates laser beams 16 in the ring laser gyro 1. Mirrors 8 are placed at the ends of the ring laser gyro block 2 to keep the laser beams 16 traveling in the block 2 for ring laser gyro operation.
One of the key factors for a long life in ring laser gyros 1 is that the cathode 7 and mirrors 8 used in the ring laser gyro 1 have a long life. The plasma environment is important in preventing the degradation of the cathode 7 and mirrors 8 and extending the life of the cathode 7 and mirrors 8. As stated previously, it has been discovered that a low level of oxygen in the plasma environment extends the life of the cathode 7 and mirrors 8 and thus, the life of the ring laser gyro 1. However, it has been difficult if not impossible to create a slight oxygen background because there are multiple oxygen sinks inside the laser cavity of the ring laser gyro.
It would be beneficial to create an environment for the cathode 7 and mirrors 8 so that the cathode 7 and mirrors 8 would not deteriorate and have a long life. As a result of a longer life for the cathode 7 and the mirrors 8, the life of the ring laser gyro 1 would be longer as well.